RB20DET 5-Speed options

[GTES-t]

I'm looking for someone who has rebuilt or configured an RB20DET 5-Speed transmission. I broke the main/output shaft in mine on a drag strip launch.

To start, I moved to England from Japan last year, and parts availability is horrible. Not like Japan, just going to the junkyard and paying ~$150-200 for one. It's hard to even find one here, and when I hear of one I haven't seen it for less then 500 pounds (~$800!!!!!).

I have researched everything I can about the RB20DET's 5-Speed FS5W71C. Which is also the transmission that the SR20DET uses. So, I compared mine to a friends SR20DET 5 Speed when his was out for a clutch change. The front bell housing is different obviously, but the rear housing is identical. The gear ratios are identical, and several internal parts, including the input shaft, are the exact same part number. (according to Nissan FAST) Now certain parts are not, but from what I've heard rumored is that those parts are stronger in the SR's tranny. (different bearing sizes for the gear set center retaining wall/housing)

Anyways, I'm trying to find out if anyone knows if or has used an SR gearbox, with the RB20's transmission bell housing installed on an RB20DET. I'm considering this option, because then I can upgrade with the TRUST 5 speed to 6 speed conversion kit later (or the next time I break the stock internals). Also, because I can get the SR20DET tranny (which is what turbo S14 200SX's are equipped with here) for 200 pounds (only ~$350).

[Doughnutdemon]

Interesting question - I'd like to know too.

[GTES-t]

I've been gone for a while on a trip. Unfortunately, the SR20DET transmission delivery was delayed until the day I left!

So, I came back to it waiting for me. I swapped out the forward half housing with the one from my RB. No issues with that. However, I do have an issue with the rear housing. It's two inches longer then the RB's. I've got to re-verify my friend's SR's rear housing and see if I screwed up or if for some reason the brit spec SR uses a different type.

Anyways, I am going to put the transmission in tomorrow morning and make sure the crossmember lines up properly (should). And that the speedometer cable will reach (it's mount location is moved back the 2 inches) and that the shifter being moved back also is still usable. The previous transmission's shifter sat forward of where I thought it should, so this may make it better.

The hard part is the fact that the front half piece of the driveshaft is 2 inches to long to fit now. So, I have to send it out to get it cut, remade to the new length, and high speed balanced.

I have pics to post later along with another update of the progress.

[sunsetsandturbos]

Hey dude,

Can you give us an update to this swap? Did everything work out ok? Hw does the transmission feel? Stonger? Gears the same? Anything else you have to mod other than the driveshaft? r32 mounts work?

Thanks for your input.

[GTES-t]

Wow, I'd forgotten all about this thread. Getting everything working ended up taking quite a bit of time. Most of the time was spent waiting for the driveshaft. Another large portion was spent trying to get alternator/battery problems sorted out due to the long parked time.

Anyways, I got everything installed. The transmission install was very easy. The new shifter location took modifying the cut-out to fit it. The driveshaft was finally replaced with a VERY NICE 1-piece!

The link in my signature has all the pics and info. The gear ratios are all the same, really there's no noticeable difference in driving except for the shifter location, which I like better. This gearbox feels stronger, but I had really abused the old one, and don't know how abused it was before I got it.

The best part of spending the time/money for this swap is that I can get replacement parts/gearbox a lot easier/cheaper. Plus if I ever feel the urge, I can upgrade to the Trust 5 to 6 speed conversion that 's available for the S13/S14 gearbox.

[sunsetsandturbos]

Thanks for your reply dude, I appreciate it.

What clutch and flywheel did you end up using?

Any little need to knows like throw out bearings from what car? or are they the same?

I may end up doing this swap myself, as the sr20 transmissions are in a much greater supply.

thanks again dude.

[GTES-t]

I used the clutch throw out bearing/sleeve I aready had. (OS Giken twin plate)
The swap doesn't change anything with the clutch set up for the RB20. Since the hybrid gearbox uses the RB20's forward housing, there are no differences in the geometry. (length/diameter/etc)